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Thomas W Scott - One of the best experts on this subject based on the ideXlab platform.
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sampling considerations for designing aedes aegypti diptera culicidae oviposition studies in iquitos peru substrate preference diurnal periodicity and Gonotrophic Cycle length
Journal of Medical Entomology, 2011Co-Authors: Jacklyn Wong, Helvio Astete, Amy C Morrison, Thomas W ScottAbstract:ABSTRACT When devising methods to sample Aedes aegypti (L.) eggs from naturally-occurring containers to investigate selective oviposition, failure to take into account certain aspects of Ae. aegypti behavior can bias study inferences. In Iquitos, Peru, we tested three assumptions related to designing Ae. aegypti oviposition field studies, as follows: 1) lining containers with paper as an oviposition substrate does not affect oviposition; 2) diurnal egg-laying activity peaks in the late afternoon or early evening, and there is little oviposition during midday; and 3) the Gonotrophic Cycle length of wild females averages from 3 to 4 d. When wild females were presented with containers lined and unlined with paper toweling, the presence of paper increased oviposition in plastic and metal containers, but had no effect in cement containers. Recording the number of eggs laid by Ae. aegypti every 2 h throughout the day delineated a bimodal diurnal oviposition pattern, with a small morning peak, decreased activity...
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longitudinal studies of aedes aegypti diptera culicidae in thailand and puerto rico blood feeding frequency
Journal of Medical Entomology, 2000Co-Authors: Thomas W Scott, Gary G Clark, Leslie H Lorenz, Priyanie H Amerasinghe, Amy C Morrison, Daniel Strickman, Pattamaporn Kittayapong, John D EdmanAbstract:We used a histologic technique to study multiple blood feeding in a single Gonotrophic Cycle by engorged Aedes aegypti (L.) that were collected weekly for 2 yr from houses in a rural village in Thailand (n = 1,891) and a residential section of San Juan, Puerto Rico (n = 1,675). Overall, mosquitoes from Thailand contained significantly more multiple meals (n = 1,300, 42% double meals, 5% triple meals) than mosquitoes collected in Puerto Rico (n = 1,156, 32% double meals, 2% triple meals). The portion of specimens for which frequency of feeding could not be determined was 31% at both sites. We estimated that on average Ae. aegypti take 0.76 and 0.63 human blood meals per day in Thailand and Puerto Rico, respectively. However, frequency of multiple feeding varied among houses and, in Puerto Rico, the neighborhoods from which mosquitoes were collected. In Thailand 65% of the mosquitoes fed twice on the same day, whereas in Puerto Rico 57% took multiple meals separated by > or = 1 d. At both sites, the majority of engorged specimens were collected inside houses (Thailand 86%, Puerto Rico 95%). The number of blood meals detected was independent of where mosquitoes were collected (inside versus outside of the house) at both sites and the time of day collections were made in Puerto Rico. Feeding rates were slightly higher for mosquitoes collected in the afternoon in Thailand. Temperatures were significantly higher and mosquitoes significantly smaller in Thailand than in Puerto Rico. At both sites female size was negatively associated with temperature. Rates of multiple feeding were associated positively with temperature and negatively with mosquito size in Thailand, but not in Puerto Rico. Multiple feeding during a single Gonotrophic Cycle is a regular part of Ae. aegypti biology, can vary geographically and under different climate conditions, and may be associated with variation in patterns of dengue virus transmission.
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detection of multiple blood feeding in aedes aegypti diptera culicidae during a single Gonotrophic Cycle using a histologic technique
Journal of Medical Entomology, 1993Co-Authors: Thomas W Scott, Gary G Clark, Leslie H Lorenz, Priyanie H Amerasinghe, Paul Reiter, John D EdmanAbstract:We evaluated a histologic technique for its usefulness in detecting multiple blood feeding by Aedes aegypti (L.) in a single Gonotrophic Cycle. To standardize the procedure, we carried out a laboratory study in which 166 mosquitoes imbibed two blood meals at known intervals. Eighty percent (78/98) of the multiple meals were detected when the interval between meals was from 1 to < to = 24 h and the time from the second meal to fixation ranged from 0 to 12 hr. At intervals outside this range, only 34% (23/68) of the multiple meals were detected. Overall, 61% (101/166) of the double meals were detected. Examination of 96 engorged Ae. aegypti collected by aspiration from inside houses in San Juan, Puerto Rico, indicated that 50% had imbibed multiple meals. Most wild-caught mosquitoes took their last meal the day before capture, and most multiple feeders fed twice on consecutive days. A dark line of digested blood, or heme, around the first meal and a physical separation between meals were the most useful histologic parameters for detecting multiple feeding in wild Ae. aegypti. An association of multiple feeding with advanced stages of oocyte development suggests that, at the time of collection, most Ae. aegypti from the study site had fed twice in each Gonotrophic Cycle. We conclude that, although it is labor intensive, histologic examination is an appropriate technique for a longitudinal, community-wide survey of multiple feeding by Ae. aegypti.
John D Edman - One of the best experts on this subject based on the ideXlab platform.
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longitudinal studies of aedes aegypti diptera culicidae in thailand and puerto rico blood feeding frequency
Journal of Medical Entomology, 2000Co-Authors: Thomas W Scott, Gary G Clark, Leslie H Lorenz, Priyanie H Amerasinghe, Amy C Morrison, Daniel Strickman, Pattamaporn Kittayapong, John D EdmanAbstract:We used a histologic technique to study multiple blood feeding in a single Gonotrophic Cycle by engorged Aedes aegypti (L.) that were collected weekly for 2 yr from houses in a rural village in Thailand (n = 1,891) and a residential section of San Juan, Puerto Rico (n = 1,675). Overall, mosquitoes from Thailand contained significantly more multiple meals (n = 1,300, 42% double meals, 5% triple meals) than mosquitoes collected in Puerto Rico (n = 1,156, 32% double meals, 2% triple meals). The portion of specimens for which frequency of feeding could not be determined was 31% at both sites. We estimated that on average Ae. aegypti take 0.76 and 0.63 human blood meals per day in Thailand and Puerto Rico, respectively. However, frequency of multiple feeding varied among houses and, in Puerto Rico, the neighborhoods from which mosquitoes were collected. In Thailand 65% of the mosquitoes fed twice on the same day, whereas in Puerto Rico 57% took multiple meals separated by > or = 1 d. At both sites, the majority of engorged specimens were collected inside houses (Thailand 86%, Puerto Rico 95%). The number of blood meals detected was independent of where mosquitoes were collected (inside versus outside of the house) at both sites and the time of day collections were made in Puerto Rico. Feeding rates were slightly higher for mosquitoes collected in the afternoon in Thailand. Temperatures were significantly higher and mosquitoes significantly smaller in Thailand than in Puerto Rico. At both sites female size was negatively associated with temperature. Rates of multiple feeding were associated positively with temperature and negatively with mosquito size in Thailand, but not in Puerto Rico. Multiple feeding during a single Gonotrophic Cycle is a regular part of Ae. aegypti biology, can vary geographically and under different climate conditions, and may be associated with variation in patterns of dengue virus transmission.
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detection of multiple blood feeding in aedes aegypti diptera culicidae during a single Gonotrophic Cycle using a histologic technique
Journal of Medical Entomology, 1993Co-Authors: Thomas W Scott, Gary G Clark, Leslie H Lorenz, Priyanie H Amerasinghe, Paul Reiter, John D EdmanAbstract:We evaluated a histologic technique for its usefulness in detecting multiple blood feeding by Aedes aegypti (L.) in a single Gonotrophic Cycle. To standardize the procedure, we carried out a laboratory study in which 166 mosquitoes imbibed two blood meals at known intervals. Eighty percent (78/98) of the multiple meals were detected when the interval between meals was from 1 to < to = 24 h and the time from the second meal to fixation ranged from 0 to 12 hr. At intervals outside this range, only 34% (23/68) of the multiple meals were detected. Overall, 61% (101/166) of the double meals were detected. Examination of 96 engorged Ae. aegypti collected by aspiration from inside houses in San Juan, Puerto Rico, indicated that 50% had imbibed multiple meals. Most wild-caught mosquitoes took their last meal the day before capture, and most multiple feeders fed twice on consecutive days. A dark line of digested blood, or heme, around the first meal and a physical separation between meals were the most useful histologic parameters for detecting multiple feeding in wild Ae. aegypti. An association of multiple feeding with advanced stages of oocyte development suggests that, at the time of collection, most Ae. aegypti from the study site had fed twice in each Gonotrophic Cycle. We conclude that, although it is labor intensive, histologic examination is an appropriate technique for a longitudinal, community-wide survey of multiple feeding by Ae. aegypti.
Heinz Mehlhorn - One of the best experts on this subject based on the ideXlab platform.
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retracted article histologic parameters for detecting multiple blood meals in aedes albopictus skuse diptera culicidae during a single Gonotrophic Cycle
Parasitology Research, 2018Co-Authors: Abeer S Yamany, Fatma K Adham, Heinz MehlhornAbstract:The histologic technique was used for its usefulness in detecting multiple blood feedings in Aedes albopictus during a single Gonotrophic Cycle. In a laboratory study, in which 200 blood-engorged Ae. albopictus mosquito females during a 3-day period were examined, 69% (138/200) of these females imbibed two blood meals when the interval between meals was from 8 to 48 h and the time between the second blood meal and fixation ranged from 0 to 32 h. At the interval outside this range, only 23% of the multiple meals were detected when using histologic parameters. Early blood meals were detected clearly within the later blood meals as a delimited body of dark digested blood with heme (H), sometimes also with pink undigested blood, the presence of an associated pale blue-staining peritrophic plug (PP), by the presence and appearance of the peritrophic membrane (PM) surrounding the meals, and a physical separation (PS) between meals. Development of the ovarian follicles including apparent dilatations was also observed. Advanced stages of oocyte development suggests that, at the time of field collection, most Ae. albopictus had fed twice in each Gonotrophic Cycle. The results obtained during this study indicated that the rate of multiple feeding can be determined using histologic technique which would be useful in evaluating the blood feeding frequency of field-caught tiger mosquitoes Ae. albopictus in endemic areas of viral pathogens.
Flavio Antonio Maes Dos Santos - One of the best experts on this subject based on the ideXlab platform.
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survival population size and Gonotrophic Cycle duration of nyssomyia neivai diptera psychodidae at an endemic area of american cutaneous leishmaniasis in southeastern brazil
Journal of Medical Entomology, 2009Co-Authors: Claudio Casanova, Delsio Natal, Flavio Antonio Maes Dos SantosAbstract:ABSTRACT The survival, absolute population size, Gonotrophic Cycle duration, and temporal and spatial abundance of Nyssomyia neivai (Pinto) were studied in a rural area endemic for American cutaneous leishmaniasis (ACL) in Conchal, Soo Paulo State, southeastern Brazil, using mark-release-recapture techniques and by monitoring population fluctuation. The monthly abundance exhibited a unimodal pattern, with forest and domicile habitats having the highest relative abundances. A total of 1,873 males and 3,557 females were marked and released during the six experiments, of which 4.1–13.0% of males and 4.1–11.8% of females were recaptured. Daily survivorship estimated from the decline in recaptures per day was 0.681 for males and 0.667 for females. Gonotrophic Cycle duration was estimated to be 4.0 d. Absolute population size was calculated using the Lincoln Index and ranged from 861 to 4,612 males and from 2,187 to 19,739 females. The low proportion of females that reach the age when they are potentially infec...
Mario H Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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host selection and Gonotrophic Cycle length of anopheles punctimacula in southern mexico
Journal of The American Mosquito Control Association, 2006Co-Authors: Armando Ulloa, Lilia Gonzalezceron, Mario H RodriguezAbstract:The host preference, survival rates, and length of the Gonotrophic Cycle of Anopheles punctimacula was investigated in southern Mexico. Mosquitoes were collected in 15-day separate experiments during the rainy and dry seasons. Daily changes in the parous-nulliparous ratio were recorded and the Gonotrophic Cycle length was estimated by a time series analysis. Anopheles punctimacula was most abundant during the dry season and preferred animals to humans. The daily survival rate in mosquitoes collected in animal traps was 0.96 (parity rate = 0.86; Gonotrophic Cycle = 4 days). The length of Gonotrophic Cycle of 4 days was estimated on the base of a high correlation coefficient value appearing every 4 days. The minimum time estimated for developing mature eggs after blood feeding was 72 h. The proportion of mosquitoes living enough to transmit Plasmodium vivax malaria during the dry season was 0.35.
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Gonotrophic Cycle and survivorship of anopheles vestitipennis diptera culicidae in two different ecological areas of southern mexico
Journal of Medical Entomology, 1998Co-Authors: Juan I Arredondojimenez, Mario H Rodriguez, Robert K WashinoAbstract:The duration of the Gonotrophic Cycle and survivorship of Anopheles vestitipennis Dyar & Knab was estimated in 2 malarious areas of Chiapas, Mexico: the Lacandon Forest and the Pacific Ocean Coastal Plain. Blood-engorged females held in an outdoor cage required 2.75 d for egg maturation, and 3.75 d for the duration of the Gonotrophic Cycle. Duration of the Gonotrophic Cycle also was estimated by parous-nulliparous dynamics for 20 consecutive days and autocorrelation time-series analysis, and by mark-recapture techniques. These methods depicted differences between the Lacandon Forest (3-d Cycle) and the Coastal Plain (2–3 d Cycles). Daily survival rates were estimated vertically and were generally higher in the Lacandon Forest (0.68) than in the Coastal Plain (0.45–0.58). The probability of mosquitoes surviving the sporogonic Cycle was 10–100 times greater in the Lacandon Forest. The pregravid rate was 8.2%, and 29.3% of females with primary follicles beyond Christophers’ stage III had traces of red blood in the gut. The 1st statistic indicated that 8.2% of females required >1 blood meal for initial egg development, the 2nd statistic indicated that 29.3% of females take >1 blood meal during a Gonotrophic Cycle. In summary, the enhanced vectorial role of this species is explained partially by high longevity and multiple blood-feeding habits.
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Gonotrophic Cycle and survivorship of Anopheles pseudopunctipennis (Diptera: Culicidae) in the Tapachula foothills of southern Mexico
Journal of medical entomology, 1994Co-Authors: Ildefonso Fernández-salas, Mario H Rodriguez, Donald R. RobertsAbstract:Mark–release–recapture experiments were conducted to determine the length of the Gonotrophic Cycle and survivorship of Anopheles pseudopunctipennis Theobald in the Tapachula foothills of southern Mexico. Separate trials with wild-caught females were conducted in the early and late dry season to examine intraseasonal differences. The Gonotrophic Cycle of insectary-reared, nulliparous females was estimated during the late dry season. A total of 5.4–5.7% of marked females was recaptured. A 3-d Gonotrophic Cycle was characteristic of wild-caught females, whereas a 4-d Gonotrophic Cycle was characteristic for insectary-reared females. Engorged, wild-caught females completed oogenesis in ≈60 h under field conditions. Blood digestion in 23.5% of 2,221 and 21.9% of 1,195 engorged, wild-caught females held in the insectary was not accompanied by egg development. Dissections of these females showed that nearly 85% were nulliparous and presumably pregravid. These statistics plus other field data were used to determine that 60% of all nulliparous entered a pregravid condition. The body size and wing length of gravids was significantly larger than pregravids. Daily survival estimates of 0.875 and 0.884 were calculated for field-collected females during the early and late dry season, respectively.
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Gonotrophic Cycle and survivorship of anopheles albimanus diptera culicidae in southern mexico
Journal of Medical Entomology, 1992Co-Authors: Mario H Rodriguez, Juan I Arredondojimenez, D N Bown, Cuauhtemoc Villarreal, Enrique Loyola, Christian E FredericksonAbstract:The length of the Gonotrophic Cycle of Anopheles albimanus was estimated by 12 mark-release-recapture studies conducted in corrals in southern Mexico from 1987 to 1990. The initial set of three mark-release studies indicated that the Gonotrophic Cycle takes at least 4 d based on the day when gravid mosquitoes were first recaptured. However, in later experiments, mosquitoes recaptured seeking hosts at 48 h after release were in Sella's and Christophers' stages I and II, but parity rates had nearly doubled, indicating that eggs may have developed in less than 48 h and that mosquitoes returned to refeed immediately following oviposition. Two Gonotrophic Cycles probably exist, one of 48 h dominated by parous mosquitoes and one of 4 d comprised of nulliparous, pregravid mosquitoes. Daily survivorship was estimated by regression from the decrease in the daily recapture rate (0.46-0.68) was less than that estimated by the parity rates (0.67-0.69), with no important differences found between wet and dry seasons. Estimates of the probability of a mosquito living long enough to transmit malaria were 2% (range, 1.8-2.5%).